BACKGROUND OF THE INVENTION
[0001] The present invention relates to a work machine cab comprising wall, floor and roof
structures enclosing a cabin space, whereby the work machine cab may be subjected
to a substantially vertical linear movement by a lifting unit associated therewith,
which lifting unit is attached with at least one securing means to a movable or immovable
carriage abutting thereto or to a separate structure therein, which lifting unit comprises
at least one guide bar and at least one actuator so as to move the work machine cab.
Such a, for instance, as a cabin in a loader for timber-transporting vehicles in order
to improve the driver's working conditions.
[0002] It is previously known to manufacture these cabs which have long since replaced,
for instance, working seats that are used in loaders and that are completely exposed
to open air.
[0003] Some significant drawbacks, however, are still associated with these prior art work
machine cabs protecting against environmental effects. Consequently, their attachment
to loader structures is considerably cumbersome, requiring lifting units of heavy
structure, which reduce the payload capacity of the truck. Mounting of the lifting
unit, on one hand, onto the work machine and, on the other hand, onto the loader,
involves a large number of working steps, which make the mounting expensive to perform.
BRIEF DESCRIPTION OF THE INVENTION
[0004] The object of the present invention is thus to provide a solution whereby the problems
resulting from the prior art drawbacks could be solved in a novel manner.
[0005] This is achieved by a work machine cab having the characteristics defined in the
claims i accordance with this invention. More precisely, the apparatus of the invention
is mainly characterized by the side wall abutting to the cabin space of the work machine
cab comprising at least one channel such, that this channel is arranged to receive
both said guide bar and one or more control means manoeuvred by the guide bar, the
actuators being arranged to generate a movement between the control means and the
guide bar integrated in the side wall with respect to each other.
[0006] The preferred embodiments of the invention are disclosed in the dependent claims.
[0007] In the specification, the terms determining the position, such as "in its upper position"
and "in its lower position" illustrate features of the invention in directions relative
to the work machine cab as shown in the attached drawings.
[0008] The invention is based on the idea that, unlike previously, the lifting unit may
be arranged as an integral part of the wall structure of the work machine cab. Integration
of the lifting unit with the wall structure of the work machine cab reduces considerably
working steps in manufacturing and mounting. In addition, the present solution substantially
simplifies and expedites the mounting of the work machine cab onto a loader on a truck,
for instance. Instead of being necessary to mount support and securing structures
required by the lifting unit to the work machine cab during manufacture, the lifting
unit may be utilized as a part of the frame structure of the work machine cab. Because
the lifting unit is ready-fitted in the work machine cab during manufacture, there
is no need to take action for mounting it on the side of the work machine cab, as
has been done previously, but it will suffice that the lifting unit be attached by
a few simple operations with securing means thereof to the structures of the truck,
for instance to the loader thereof or to a vertical pillar supporting it.
[0009] Other considerable advantages are also achieved by means of the invention. So, for
instance, the integration of the lifting unit with the wall structure of the work
machine cab reduces the need for space previously required between the work machine
cab and the loader. This cleared space may now be utilized, for instance, for making
the cab larger without a risk of exceeding the statutory total width of the truck.
Because integration allows simplification of necessary support structures, considerable
savings in construction material are also achieved. Naturally, this saving is of economical
importance in the manufacture of the work machine cab, but in particular, it is of
importance as the loading capacity of the truck becomes larger in accordance with
the reduced weight caused by less material.
[0010] As the lifting unit constitutes part of the wall structure of the work machine cab,
there is a possibility, unlike previously, that the wall on the side of the lifting
unit is utilized for providing a window opening therein. A window opening of this
kind may be utilized by the driver, because the lifting unit of the invention withdraws
from the window opening as a result of the lifting movement. This both improves the
work ergonomics in the cabin space and increases the occupational safety in the work
machine cab. Because the addition of the window opening widens the driver's visual
field range from the left side up to the right side of the work machine cab, unlike
previously, the work machine cabs need not be manufactured such that they would be
positioned separately on the right side or the left side of the truck, but from the
same work machine cab it is possible to control the whole visual field required.
[0011] The work machine cab of the invention also reduces the need for maintenance. By integrating
the lifting unit with the wall structure, the lifting unit will be better protected
against fouling and impacts than previously. Naturally, this also increases the operational
reliability of the work machine cab, which in turn increases the effective working
hours of the truck.
[0012] Other advantages provided by the invention are disclosed in the following in connection
with the detailed description of the particular embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] In the following, a preferred embodiment of the invention will be described in greater
detail, with reference to the attached drawing, in which
Figure 1 is a schematic axonometric view of a work machine cab of the invention in
its lower position;
Figure 2 shows the work machine cab of Figure 1 in its upper position;
Figure 3 shows the work machine cab of Figure 1 as secured to a pillar of a loader
in the truck;
Figure 4 shows a schematic horizontal section of a wall in the work machine cab of
the invention at A - A in Figure 1, the work machine cab being in its lower position;
Figure 5 shows a schematic vertical section of a wall in the work machine cab of the
invention at B - B in Figure 2, the work machine cab being in its upper position;
and
Figure 6 shows a schematic horizontal section of a wall in the work machine cab of
the invention at C in Figure 4.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
[0014] In the present figures, the work machine cab is not shown in scale, but the figures
are schematic, illustrating the principle of the structure and operation of a preferred
embodiment. Thus, structural parts indicated by reference numerals in the accompanying
figures correspond to the structural parts with like reference numerals in this specification.
[0015] So, Figure 3 shows an embodiment of the present work machine cab 1 as secured, by
way of example, to a vertical pillar 2 of a loader in a truck, the figure showing
just the vertical pillar with the work machine cab. This kind of a work machine cab
may naturally be utilized in any kind of movable or immovable carriage as well as
in said truck. The work machine cab in the form shown in the figure comprises a cabin
space 3 furnished and equipped in the manner known per se, which will not be described
in greater detail in this connection. This cabin space is surrounded, as usual, on
six sides by wall, floor and roof structures, which are provided with necessary window
surfaces and doors. For the sake of simplicity, in this connection the figures only
show the main frame structures of the work machine cab, and consequently, apart from
the earlier mentioned furnishings and equipment, also windows, doors and optional
furnishings and equipment to be mounted on the outer surface of the work machine cab,
are omitted in the figures.
[0016] The work machine cab 1 is arranged to be controllable in a translational movement,
more precisely, in a substantially vertical linear movement, with a lifting unit 4
associated therewith. The linear movement is produced in relation to the carriage
abutted on the work machine cab or a separate structure thereof, to which the lifting
unit is attached with at least one securing means 5 in accordance with Figure 3. These
securing means are also visible in other figures, in which the work machine cab is
shown detached from its operating environment.
[0017] The lifting unit 4 comprises at least one guide bar 8 integrated with a side wall
7 as shown in the figures. In the present structure there are two guide bars consisting
of, for instance, linear guide bars opposite one another as shown in Figure 6. These
linear guide bars preferably constitute part of the frame structure of the work machine
cab 1, bracing the structure of the work machine cab, but just as well the linear
guide bars may be attached to the frame structure of the work machine cab, thus contributing
to the bracing of the structure of the work machine cab. The length of the guide bars
is determined by the length of the desired linear movement. In the embodiment of the
figures, the guide bars extend from the floor of the work machine cab substantially
to a window opening 9 to be provided in the side wall 7. Thus it is possible to maximize
the light opening of the window, yet providing a sufficient lifting height for the
work machine cab.
[0018] The guide bars, together with the side wall, define therebetween a channel 10, in
which one or more control means 11 are arranged to move. In this preferred embodiment
the control means comprises a means that extends substantially throughout the entire
height of the side wall 7, whereby a sufficient rigidity is provided also at the extreme
end of the vertical lifting movement of the work machine cab.
[0019] The control means 11 may consist, for instance, of at least one slide connected to
the linear guide bar 8, as best appears from Figures 1 and 2. From this slide protrude
securing means 5 wherewith the lifting unit 4 and the relating work machine cab 1
are attached to a loader, for instance.
[0020] At least one actuator 12, whereby the mutual movement between the control means 11
and the guide bars 8 is provided, is arranged to control the movement of the lifting
unit 4. This actuator advantageously comprises a pressure-medium-operated cylinder,
and consequently it may be either a hydraulic or a pneumatic cylinder. On the other
hand, it is conceivable that the movement of the lifting unit is also produced by
an electric motor, in which case the actuator 12 may comprise, for instance, a spindle
motor or a step motor. Naturally, the movement of the lifting unit may also be controlled
by any systems known per se, which are not specified herein in detail. So, the actuator
may control a cable arrangement, which for instance through a tackle arrangement,
transfers the movement to the work machine cab.
[0021] In the preferred embodiment of the figures, the actuator 12 controlling the movement
of the lifting unit 4 extends from the lower edge 13 of the control means 11 in the
lifting unit to the roof structures 14 of the work machine cab 1. Even though the
figures show that the actuator extends over the window opening 9 of the side wall
7, nothing prevents the lifting unit from being provided with, for instance, two actuators
mounted beside the guide bars 8, which actuators are closable in channels arranged
in the side wall outside the window opening.
[0022] The present work machine cab 1 operates as follows. When the work machine cab 1 is
in its lower position as shown in Figure 1, the driver enters the cabin space 3. While
in the cabin space, he or she starts the actuator 12 controlling the operation of
the lifting unit 4. The actuator moves the work machine cab vertically upwards along
the control means 11. As the control means is released from the channel 10 provided
in the wall structure 7 of the work machine cab, the lifting-unit-side window opening
9 of the cabin space is cleared at the same time, which permits the driver to have
a substantially unlimited visibility in all directions from the cabin space. On reaching
its top height, i.e. the working height of the present embodiment locating 1000 to
1500mm higher up, the actuator stops automatically and the lifting unit is locked
into place in this upper position. When necessary, the locking may utilize, for instance,
gripping means arranged in the slide constituting the control means, which gripping
means, through their operation, prevent the cabin space from sliding downwardly.
[0023] For instance, once the loading work is completed, the lifting unit 4 is released
to operate and the work machine cab 1 is controlled to descend towards its rest position,
which is its lower position. The control means 11 is transferred along the guide bars
8 back to the channel 10 in the wall structure, retracting substantially for the entire
length into the channel. When substantially the entire length of the control means
is retracted in the channel, the driver may step down from the cabin space.
[0024] It is apparent to a person skilled in the art that as technology advances, the basic
idea of the solution described above may be implemented in a variety of ways. The
disclosed solution for the work machine cab and the embodiments thereof are thus not
limited to the above examples, but they may vary within the scope of the claims.
1. A work machine cab (1) comprising wall, floor and roof structures enclosing a cabin
space (3), whereby
the work machine cab may be subjected to a substantially vertical linear movement
by a lifting unit (4) associated therewith, which
lifting unit is attached with at least one securing means (5) to a movable or immovable
carriage abutting thereto or to a separate structure therein, which
the lifting unit (4) comprises at least one guide bar (8) and at least one actuator
(12) so as to move the work machine cab (1),
characterized in that
the side wall (7) abutting to the cabin space (3) of the work machine cab (1) comprises
at least one channel (10) such, that
this channel is arranged to receive both said guide bar (8) and one or more control
means (11) manoeuvred by the guide bar,
the actuators (12) are arranged to generate a movement between the control means and
the guide bar integrated in the side wall with respect to one another.
2. The work machine cab (1) of claim 1, characterized in that the actuator (12) comprises a pressure-medium-operated cylinder.
3. The work machine cab (1) of claim 2, characterized in that the actuator (12) comprises a hydraulic cylinder.
4. The work machine cab (1) of claim 1, characterized in that the actuator (12) comprises a spindle motor.
5. The work machine cab (1) of any one of the preceding claims, characterized in that the lifting unit (4) comprises linear guide bars attached to the frame of the side
wall (7), in which liner guide bars there is arranged at least one slide constituting
the control means (11), which slide comprises said securing means (5).
6. The work machine cab (1) of any one of claims 1 to 4, characterized in that the lifting unit (4) comprises linear guide bars constituting part of the frame of
the side wall (7), in which liner guide bars there is arranged at least one slide
constituting the control means (11), which slide comprises said securing means (5).
7. The work machine cab (1) of any one of the preceding claims, characterized in that the control means (11) extends substantially throughout the entire height of the
side wall (7).
8. The work machine cab (1) of claim 6 or 7, characterized in that in the lifting movement of the work machine cab (1) the control means is arranged
to clear the window opening (9) in the side wall (7).